SESSION IV 199 Maybe we can use the same illustration as that of the photograph of Shot Oak (Figure 27) we presented a while ago. In this case, there was a giant cciumnfrom this one detonation over the north region at Eniwetok. The fallout from this shot came right across the north- western edge of the atoll, We dubbed this one ‘the manurc spreader" shot, for in making the reconnaissance sweeps over the atoll we saw a brilliant green band inside the rim of the atoll, You could fly from the clear blue waters of the lagoon overthis green band, which per- sisted for several days, and the radiation instruments immediately would jump several orders of magnitude. It was obvious that the detonation had converteda good dealof the calcium carbonate, to take one element, into an oxide. The oxide had dropped in the waters to become hydroxide. Being soluble, it was picked up in an explosion of plant growth. There were other elements involved in this, too. In other words, nutritive media cropped in the sea had stimulated a very great growth of plants, in which one could find the concentrated radionuclides responsible for the jump in radiation levels, Or, you can carry this still further. In the early days of planning at Hanford the cooling ponds were thermal coolers, as we originally designed them. These sceaming vats had great masses of algae around the edge, and they still do. The algae in turn absorbed the radiation, At the time, there was very serious consideration given to a plan to simply collect the plant growths and put them ina disposal pit, since they blotted up the radiation very effectively. EISENBUD: Lauren, iron-55 is an interesting nuclide. have you looked foriron-55 in the fish over the atoll? DONALDSGN: EISENBUD: Yes. Have you found evidence of concentration? DONALISON: Yes. trated radionuclides. EISENBUD: I wonder, In fact it was one of the most highly concen- I would think so. DUNHAM: Myrecollection from a visit to Bermuda a few years ago is that one of the marine scientists there said that iron availability in the waters around there was the limiting factor in perhaps the whole food chain inasmuch as one of the key algae couldn't go farther than the amountof iron available.